Thermocouples have long been used in gas-powered appliances for generating a small amount of electric current. Typically a thermocouple is placed in the pilot flame to generate just enough power to keep a fuel control valve open. This operates as a safety precaution so that the absence of power from the thermocouple cuts off the flow of fuel. There is sufficient power from such a thermocouple for opening such a valve, which is commonly reset manually, let alone operate a blower or auxiliary devices.
Electric power can also be generated by photovoltaic devices. U.S. Pat. No. 3,188,836 by Kniebes describes use of emissive radiation to generate power to control a valve for a gas lamp. This was, in effect, a replacement for a thermocouple.
Rather different technology involves use of photoelectric devices which change resistance, for example, when illuminated. These devices, in effect, as switches for controlling current from sources of electric power. These systems are not self powered since the photoelectric devices do not generate electricity. Exemplary of use of photoelectric devices in appliance control can be seen in U.S. Pat. No. 2,306,073.
U.S. Pat. No. 3,331,701 by Werth provides the first known description of a thermophotovoltaic power producing device using silicon cells. The efficiency of silicon solar cells has been optimized to produce electric power with an efficiency of about 2.6% using a tungsten filament heated to about 2200.degree. K. as the heat source. This would be no more than marginally suitable for a self-powered gas fired appliance as provided in practice of this invention. U.S. Pat. No. 4,906,179 by Goldstein, et al., describes the use of selective emissive burner in self powered appliances.
This invention relates to burners containing narrow band selective emitters on their emissive surface(s) which is the subject of a co-pending application. The radiant energy may be used in a variety of applications such as gas range cooking, and oven cooking by matching the near IR emission of selected supermitters to that for a strongly absorbing region by the food. The key to the use of these devices is an optical container that transmits the selective emissions.
Currently gas cooking equipment often create pollution in the home or commercial facility. In addition an open flame is often the cause of fires, injuries, and even worse. The move to energy conservation after the first oil shock and the continuing rise in energy cost has lead to new construction techniques and retrofits that make commercial building, factories and dwellings nearly air tight. Thus the need for radiant cooking with lower pollution emissions and thus the need for efficient energy use such as is possible with selective emitters. Other devices that use selected photon wavelengths can also be constructed on this same principal e.g. photochemical reactors.